Currently, the following methods for a lossless compression of data, in particular image data, are known:    1. JPEG-LS (LS=Lossless) (e.g. published in ISO/IEC International Standard 14495-1 (JPEG-LS Part 1),    2. JPEG2000-Lossless (e.g. published in ISO/IEC International Standard 15444-1 (JPEG 2000 Part 1)),    3. Lossless-JPEG (e.g. published in ISO/IEC International Standard 10918-1 (JPEG Part 1), and ISO/IEC International Draft Standard 10918-2 (JPEG Part 2),    4. RLE (e.g. published in Digital Imaging and Communications in Medicine (DICOM), PS 3.5-2006, Annex G, “Encapsulated RLE compressed Images”, published by: National Electrical Manufacturers Association).
The method RLE is also known as the so-called run length compression.
In table 1, a representation of (numerical) values to be coded with the data type byte (that is, 8 bit) is shown, for example. In the first row, arbitrary numerical values can be seen. These numerical values can also represent grey values of a medical image. The corresponding numerical value is represented with corresponding zeroes and ones from bit0 to bit7 in every column.
Conventional compression methods—represented in a simplified manner—run every column from bit0 to bit7 and code the corresponding numerical value of the first row, represented in bit0 to bit7, with a suitable code.
For example, the frequency of a numerical value in a row of numerical values could be determined. A Huffman coding could for example be used for this.
TABLE 1Example for 20 numerical values, data type byte52370186720017451257781472711218316Bit011100101101100000010Bit101101100000110001111Bit211100000111111000011Bit300000010110011011010Bit401001001000000000110Bit500000000100000000010Bit600000110000010010000Bit700000010000000000000
The known method is disadvantageous in that the code used for coding has to be disclosed to a decoder for decoding, whereby a so-called overhead forms with complicated codes.